Social categorization is a universal mechanism for making sense of a vast social world with
roots in perceptual, conceptual, and social systems. These systems emerge strikingly early …

According to Graham and colleagues (2013), a “first draft” of moral cognition emerges early
and universally in development and is then gradually revised by experience and culture. In …

Whether upheld as heroic or reviled as terrorism, people have been willing to lay down their
lives for the sake of their groups throughout history. Why? Previous theories of extreme self …

To successfully navigate their social world, humans need to understand and map enduring
relationships between people: Humans need a concept of social affiliation. Here I propose …

Imitation is a deeply social process. Here, I review evidence that children use imitation as a
means by which to affiliate with others. For example, children imitate the actions of others …

Collective ritual is virtually omnipresent across past and present human cultures and is
thought to play an essential role in facilitating cooperation, yet little is known about its …

Beginning in infancy, children expect individuals in a group to care for and be loyal to in-
group members. One prominent cue that children use to infer that individuals belong to the …

Cumulative culture, where innovations are incorporated progressively into a population's
stock of skills and knowledge, generating more sophisticated repertoires, is a core aspect of …

The imagination is central to human social life but undervalued worldwide and
underexplored in psychology. Here, we offer Possible Worlds Theory as a synthetic theory of …

Homophily structures human social networks: people tend to seek out or be attracted to
those who share their preferences or values, and to generally expect social connections …